Conventional embedded systems are designed to control a wide variety of equipment, where the customer (not the system vendor) has the responsibility of choosing the equipment, connecting the equipment to the system, and making the system work. When such a system is delivered to large numbers of end users (many thousands) it becomes necessary for the system to be easily configured and to be error-proofed against mistakes made by the customer. Complicating the problem, the variety of equipment in the field is large and the vendor of each piece of equipment determines its properties and its interfaces. A solution must accommodate such variability, including differences in the electrical interfaces and the higher-level protocols, while still providing a system that is easily configured by the customer.
In most local area networks, nodes have IDs that can identify the physical nodes (e.g., their addresses), however there is no way for a node to determine the physical node topology. In some local area networks (e.g., those using CAN), nodes do not even have a physical address. When a node cannot determine the physical node topology, in the event of an anomaly it is extremely difficult for a technician to diagnose and locate the malfunctioning piece of equipment. In order to facilitate equipment installation and provide meaningful diagnostics to technicians and users, a means of providing a node with the physical node topology is desirable.
While most local networks have a forced topology of a star or a bus, either of these network topologies can cause cable routing difficulties. An automobile usually has a concentration of equipment in the trunk with additional equipment located throughout the vehicle. Employing a network with a star topology necessitates routing many individual cables from a hub to each piece of equipment, resulting in the use of longer cables than are necessary for components that are often located adjacent to one another. Employing a network with a bus topology necessitates routing a single CAN network cable throughout the vehicle, resulting in the difficult task of optimizing the route of one cable throughout the entire automobile. Moreover, employing a single CAN network cable increases both the possibility of a single point failure of the network and the impact of such a failure should one occur. Accordingly, there is a need for a means of reducing the cable routing difficulties of the customer while improving the reliability of the entire network.
Related U.S. Pat. No. 6,161,066 assigned to Wright et al. (Wright) describes a vehicle-based control system that employs a multiple control unit architecture. However, as disclosed by Wright, the entire control system will fail should the IDB fail because no piece of equipment will be controllable by the realtime microcontroller. U.S. patent application U.S. 2001/0041956 A1 assigned to Wong et al. (Wong) describes an automobile information system. Wong discloses an automobile information system that facilitates communication within clusters of components and among various clusters. However, similar to Wright, if the primary bus fails then the entire automobile information system fails. Therefore there is a need to eliminate the possibility of a single point failure of an entire vehicle network due to a single cable failure.
As a result of the aforementioned problems, there is a need for a new and improved communication network for use in an automobile. The new and improved communication network should address and overcome the problems as outlined above.